Loop goal engineering

Loop & Goal Engineering

Author the artifacts that drive autonomous agent runs: loop prompts (re-run cold each iteration until a backlog is done), goal conditions (machine- or evaluator-checkable completion criteria), and the long-horizon file scaffold that carries state between iterations.

The runtime primitives exist — Claude Code /goal and /loop, Stop hooks, Codex Goal Mode, bash while-loops. They all assume the human can already write a good loop prompt or goal condition. That authoring step is this skill's job.

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Step 1 — Classify the Deliverable

User wants	Deliverable	Primary reference
Agent grinds through a backlog / overnight run	Loop prompt (+ scaffold files)	references/loop-patterns.md
Agent keeps working until X is true	Goal condition	references/goal-specs.md
Multi-hour/multi-day autonomous project	Four-file scaffold + loop prompt + goal	both
A check that must gate with zero exceptions	Stop-hook script spec	goal-specs.md §2

If the request is really a one-shot prompt with no iteration ("write a prompt that refactors this file"), hand off to the prompt-engineering skill.

Step 2 — Pick the Harness

Use the harness selection table in references/loop-patterns.md §1. Ask at most one question if the target runtime is ambiguous (Claude Code vs Codex vs raw bash loop) — it changes the output format:

• Claude Code /goal → condition must be provable from the agent's own transcript output (the evaluator runs no commands itself)
• Codex Goal Mode → Goal / Context / Constraints / Done-when skeleton
• Stop hook → the condition becomes a script with exit codes
• Bash/Ralph loop → full loop prompt + four-file scaffold + safety rails

Step 3 — Draft

Loop prompts: apply the ten rules in loop-patterns.md §2 — one task per iteration, state in files/git, search-before-assuming, no placeholders, in-iteration verification, protected tests, idempotency, per-iteration commits, bounds, one-deliverable scope. Start from the template in §4.

Goal conditions: apply the four-part anatomy in goal-specs.md §1 — measurable end state, stated proof check, constraints, bound. Use the skeletons in §2 and the vague-goal rewrite table in §4.

Scaffolds: generate the four files (spec / plan / runbook / status log) per loop-patterns.md §3, with per-milestone validation commands in the plan.

Step 4 — Lint (mechanism before judgment)

Run the deterministic checker on every drafted goal condition or loop prompt before delivering it:

PY=$(command -v python3 || command -v python)
"$PY" "${CLAUDE_PLUGIN_ROOT}/scripts/check-goal.py" <draft-file> --json
# or pipe: echo "<draft>" | "$PY" "${CLAUDE_PLUGIN_ROOT}/scripts/check-goal.py" - --json

The script flags: missing named command, vague success adjectives, missing scope guard, missing bound, and seven of the eight gameability signatures (G1-G7 in goal-specs.md §3). Fix CRITICAL and WARNING findings, then re-run. The script exits 1 when findings exist — that's signal, not failure.

Then apply judgment the script can't: G8 (revert-satisfiability — could the agent pass by reverting to the original state?), whether the check is semantically sufficient (a passing test suite that doesn't cover the feature proves nothing), whether the goal is satisfiable at all, and whether two experts would agree on pass/fail.

Step 5 — Deliver

Same contract as prompt-engineering: a paste-ready block (or file set), one line stating the target harness and what was optimized, and setup notes only when genuinely needed (e.g., "save as PLAN.md in repo root", "requires a Stop hook registered in settings.json").

For loop deliverables, ALWAYS include the safety footer when the run is unattended: sandbox/worktree advice, credential scope, blast-radius constraints (loop-patterns.md §5). Never deliver an unbounded loop.

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Hard Rules

• NEVER deliver a goal condition without a named command/check, a scope guard, and a bound. "Tests pass" alone is a documented failure mode.
• NEVER deliver a loop prompt that allows multiple tasks per iteration.
• NEVER let the condition's own success criteria be editable by the agent (tests, scoring scripts) without an explicit protection constraint.
• NEVER present "goal engineering" as established vocabulary in delivered artifacts — the vendors' terms are Goal Mode, /goal conditions, and "Done when" criteria. (Using the phrase conversationally is fine.)
• For Claude Code /goal: ALWAYS instruct the agent to show evidence (command output) in its transcript — the evaluator cannot run commands.

Reference Files

File	Read when
references/loop-patterns.md	Authoring loop prompts, choosing a harness, building the four-file scaffold, unattended-run safety
references/goal-specs.md	Authoring goal conditions, hardening against reward hacking, vague-goal rewrites

Related: prompt-engineering skill (single-shot prompts, system prompts, CLAUDE.md/AGENTS.md), prompt-debugger agent (F8 category diagnoses loop and goal failures in prompts that already misbehaved).